Studies of adults with attention deficit disorder have been initiated to examine familial prevalence of the disorder, as well as aspects of comorbidity, personality profile and assortative mating. A pilot study of 55 adult persons reporting a diagnosis of attention deficit disorder, is focusing on construction of a personality profile as assessed by the NEO Personality Inventory of McCrae and Costa. This is of interest both because of the multiple reports of consistent personality aspects such as impulsivity and excitement seeking associated with this disorder, and because of the newly reported association of certain dimensions of personality, such as novelty/excitement seeking, with polymorphic variants at loci associated with neurotransmitter activity. The data collected have shown multiple significant departures from established norms, particularly in the neuroticism and conscientiousness domains and their associated facets.